<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        canvas {
            border: 1px solid #ccc;
        }
    </style>
</head>
<body>
<canvas width="600" height="400"></canvas>
<script>
    var myCanvas = document.querySelector('canvas');
    var ctx = myCanvas.getContext('2d');
	
	// ctx.translate(100,100);
	// ctx.scale(0.5,1);
	// ctx.rotale(Math.PI/6);
	var startAngle = 0;
	ctx.translate(150,150);
	setInterval(function(){
		startAngle += Math.PI/180;
		ctx.rotate(startAngle);
		ctx.strokeRect(-50,-50,100,100);
	},500);
</script>
</body>
</html>